A single ${\mathrm{Ba}}^{+}$ atom was confined in a radio-frequency ion trap and cooled by near-resonant laser light. Quantum jumps into and out of the metastable 5d $^{2}D_{5/2}$ level were observed that followed the expected exponential distribution in dark periods to good agreement. Measurement of quantum-jump distributions together with careful measurements of the absolute partial pressures of all residual gas species enabled accurate measurements of the quenched 5d $^{2}D_{5/2}$ lifetime as a function of quenching gas pressure. Measurements of quenching were observed at pressures where the mean collision rate was on the order of 1 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The results yielded quenching rate constants for the metastable level for a series of gases that typically make up the residual gas environment of ultra-high-vacuum systems ( ${\mathrm{H}}_{2}$ , He, ${\mathrm{CH}}_{4}$ , ${\mathrm{H}}_{2}$ O, CO, ${\mathrm{N}}_{2}$ , Ar, and ${\mathrm{CO}}_{2}$ ) together with an improved value of the ${5}^{2}$ ${\mathrm{D}}_{5/2}$ radiative lifetime of ${t}_{0}$ =34.5\ifmmode\pm\else\textpm\fi{}3.5 s. The above quenching rate constants were then compared with classical ion-molecule collision theory. It was found that the quenching rates for molecular gases were comparable to the classical collision rates, while the rates for atomic gases were considerably lower.A single ${\mathrm{Ba}}^{+}$ atom was confined in a radio-frequency ion trap and cooled by near-resonant laser light. Quantum jumps into and out of the metastable 5d $^{2}D_{5/2}$ level were observed that followed the expected exponential distribution in dark periods to good agreement. Measurement of quantum-jump distributions together with careful measurements of the absolute partial pressures of all residual gas species enabled accurate measurements of the quenched 5d $^{2}D_{5/2}$ lifetime as a function of quenching gas pressure. Measurements of quenching were observed at pressures where the mean collision rate was on the order of 1 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The results yielded quenching rate constants for the metastable level for a series of gases that typically make up the residual gas environment of ultra-high-vacuum systems (${\mathrm{H}}_{2}$, He, ${\mathrm{CH}}_{4}$, ${\mathrm{H}}_{2}$O, CO, ${\mathrm{N}}_{2}$, Ar, and ${\mathrm{CO}}_{2}$) together with an improved value of the ${5}^{2}$${\mathrm{D}}_{5/2}$ radiative lifetime of ${t}_{0}$=34.5\ifmmode\pm\else\textpm\fi{}3.5 s. The above quenching rate constants were then compared with classical ion-molecule collision theory. It was found that the quenching rates for molecular gases were comparable to the classical collision rates, while the rates for atomic gases were considerably lower.

Physical Review AMar 1, 199075 citations

Laser cooling and quantum jumps of a single indium ion

E. Peik, Guenter Hollemann, HERBERT WALTHER

We performed laser spectroscopy of ${\mathrm{In}}^{+}$ ions stored in a radio-frequency trap. The 5 ${\mathit{s}}^{2}$ $^{1}$ ${\mathit{S}}_{0}$ \ensuremath{\rightarrow}5s5p $^{3}$ ${\mathit{P}}_{1}$ transition at 230.6 nm was excited and its hyperfine splitting and isotope shift have been measured. The lifetime of the $^{3}$ ${\mathit{P}}_{1}$ state was measured using intensity modulated laser excitation: \ensuremath{\tau} ${(}^{3}$ ${\mathit{P}}_{1}$ )=0.44(4) \ensuremath{\mu}s. A single indium ion was laser cooled using this intercombination line and dark periods in the fluorescence were observed when the metastable $^{3}$ ${\mathit{P}}_{0}$ state was populated by a magnetic dipole decay from $^{3}$ ${\mathit{P}}_{1}$ . The radiative lifetime of the forbidden transition $^{3}$ ${\mathit{P}}_{0}$ ${\ensuremath{\rightarrow}}^{1}$ ${\mathit{S}}_{0}$ was determined from the duration of the dark periods: \ensuremath{\tau} ${(}^{3}$ ${\mathit{P}}_{0}$ )=0.14(2) s. This value is compared to calculations based on perturbation theory. Prospects for an optical frequency standard using the narrow 5 ${\mathit{s}}^{2}$ $^{1}$ ${\mathit{S}}_{0}$ \ensuremath{\rightarrow}5s5p $^{3}$ ${\mathit{P}}_{0}$ resonance at 236.5 nm of a single laser-cooled indium ion are discussed.We performed laser spectroscopy of ${\mathrm{In}}^{+}$ ions stored in a radio-frequency trap. The 5${\mathit{s}}^{2}$ $^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}5s5p $^{3}$${\mathit{P}}_{1}$ transition at 230.6 nm was excited and its hyperfine splitting and isotope shift have been measured. The lifetime of the $^{3}$${\mathit{P}}_{1}$ state was measured using intensity modulated laser excitation: \ensuremath{\tau}${(}^{3}$${\mathit{P}}_{1}$)=0.44(4) \ensuremath{\mu}s. A single indium ion was laser cooled using this intercombination line and dark periods in the fluorescence were observed when the metastable $^{3}$${\mathit{P}}_{0}$ state was populated by a magnetic dipole decay from $^{3}$${\mathit{P}}_{1}$. The radiative lifetime of the forbidden transition $^{3}$${\mathit{P}}_{0}$${\ensuremath{\rightarrow}}^{1}$${\mathit{S}}_{0}$ was determined from the duration of the dark periods: \ensuremath{\tau}${(}^{3}$${\mathit{P}}_{0}$)=0.14(2) s. This value is compared to calculations based on perturbation theory. Prospects for an optical frequency standard using the narrow 5${\mathit{s}}^{2}$ $^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}5s5p $^{3}$${\mathit{P}}_{0}$ resonance at 236.5 nm of a single laser-cooled indium ion are discussed.

European Quantum Electronics Conference (EQEC)Aug 24, 20052 citations

A single

{\mathrm{Ba}}^{+}

atom was confined in a radio-frequency ion trap and cooled by near-resonant laser light. Quantum jumps into and out of the metastable 5d

^{2}D_{5/2}

level were observed that followed the expected exponential distribution in dark periods to good agreement. Measurement of quantum-jump distributions together with careful measurements of the absolute partial pressures of all residual gas species enabled accurate measurements of the quenched 5d

^{2}D_{5/2}

lifetime as a function of quenching gas pressure. Measurements of quenching were observed at pressures where the mean collision rate was on the order of 1 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The results yielded quenching rate constants for the metastable level for a series of gases that typically make up the residual gas environment of ultra-high-vacuum systems (

{\mathrm{H}}_{2}

, He,

{\mathrm{CH}}_{4}

{\mathrm{H}}_{2}

O, CO,

{\mathrm{N}}_{2}

, Ar, and

{\mathrm{CO}}_{2}

) together with an improved value of the

{5}^{2}

{\mathrm{D}}_{5/2}

radiative lifetime of

{t}_{0}

=34.5\ifmmode\pm\else\textpm\fi{}3.5 s. The above quenching rate constants were then compared with classical ion-molecule collision theory. It was found that the quenching rates for molecular gases were comparable to the classical collision rates, while the rates for atomic gases were considerably lower.

We performed laser spectroscopy of

{\mathrm{In}}^{+}

ions stored in a radio-frequency trap. The 5

{\mathit{s}}^{2}

^{1}

{\mathit{S}}_{0}

\ensuremath{\rightarrow}5s5p

^{3}

{\mathit{P}}_{1}

transition at 230.6 nm was excited and its hyperfine splitting and isotope shift have been measured. The lifetime of the

^{3}

{\mathit{P}}_{1}

state was measured using intensity modulated laser excitation: \ensuremath{\tau}

{(}^{3}

{\mathit{P}}_{1}

)=0.44(4) \ensuremath{\mu}s. A single indium ion was laser cooled using this intercombination line and dark periods in the fluorescence were observed when the metastable

^{3}

{\mathit{P}}_{0}

state was populated by a magnetic dipole decay from

^{3}

{\mathit{P}}_{1}

. The radiative lifetime of the forbidden transition

^{3}

{\mathit{P}}_{0}

${\ensuremath{\rightarrow}}^{1}$

{\mathit{S}}_{0}

was determined from the duration of the dark periods: \ensuremath{\tau}

{(}^{3}

{\mathit{P}}_{0}

)=0.14(2) s. This value is compared to calculations based on perturbation theory. Prospects for an optical frequency standard using the narrow 5

{\mathit{s}}^{2}

^{1}

{\mathit{S}}_{0}

\ensuremath{\rightarrow}5s5p

^{3}

{\mathit{P}}_{0}

resonance at 236.5 nm of a single laser-cooled indium ion are discussed.